Substrate processing method, substrate processing apparatus and a computer-readable storage medium

ABSTRACT

A processing method in one embodiment includes: a step that takes an image of the end face of a reference substrate, whose warp amount is known, over the whole periphery thereof using a camera to obtain shape data of the end face of the reference substrate over the whole periphery of the reference substrate; a step that takes an image of the end face of a substrate over the whole periphery thereof using a camera to obtain shape data of the end face of the substrate over the whole periphery of the substrate; a step that calculates warp amount of the substrate based on the obtained shape data; a step that forms a resist film on a surface of the substrate; a step that determines the supply position from which an organic solvent is to be supplied to a peripheral portion of the resist film and dissolves the peripheral portion by the solvent supplied from the supply position to remove the same from the substrate.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 15/437,885,filed Feb. 21, 2017, and claims the benefit of Japanese PatentApplication No. 2016-031369, filed on Feb. 22, 2016, the entireties ofwhich are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a substrate processing method, asubstrate processing apparatus and a computer-readable storage medium.

BACKGROUND OF THE INVENTION

At present, when a substrate (e.g., a semiconductor wafer) ismicromachined to manufacture a semiconductor device, a pattern(patterned projections/recesses) (e.g., a resist pattern) is generallyformed on a substrate by means of a photolithography technique. Theprocess for forming a resist pattern on a semiconductor wafer includes,for example, a resist-film forming step that forms a resist film(coating film) on a surface of a wafer, an exposure step that exposesthe resist film along a predetermined pattern, and a developing stepthat develops the exposed resist film by reacting the same and adeveloper.

In general, a spin coating method that drops a resist liquid onto asurface of a wafer while rotating the wafer is employed to perform theresist-film forming step. Thus, in general, a resist film is formed allover the surface of the wafer. When such a wafer W is transported by atransport arm, the resist film adheres to the transport arm upongripping of the peripheral portion of the wafer W by the transport arm.In this case, a succeeding wafer may be contaminated by residue of theresist film adhering to the transport arm. Thus, in some cases, aperiphery removal process for removing a resist film present on theperipheral portion of a wafer is performed.

Patent Document 1 (JP11-333355A) discloses, as an example of theperiphery removal process, a method for removing a peripheral portion ofa resist film along a periphery of a wafer (called “edge rinsingprocess”). The method supplies, after forming the resist film on thewafer surface, an organic solvent to a portion of the resist film havingbeen solidified and positioned on the peripheral portion of the wafer(i.e., the peripheral portion of the resist film) while rotating thewafer. Patent Document 2 (JP2002-158166A) discloses, as another exampleof the periphery removal process, a method (periphery exposing anddeveloping process) for removing a peripheral portion of a resist filmalong the periphery of a wafer. The method exposes the peripheral areaof the wafer inwardly extending from the periphery of the wafer andhaving a predetermined radial width, and develops the same area.

Since a wafer is manufactured through various steps, the wafer may bewarped before the wafer is subjected to a certain fine processing step.In addition, in order to form a resist film on a surface of a wafer, thewafer is subjected to a heating process and a cooling process afterapplying a resist liquid to the surface of the wafer. Thus, the wafermay be warped due to the heating and/or cooling of the wafer. Especiallyin recent years, the development of 3D NAND flash memories has beenprogressing. Since the memory is manufactured through many steps eachfor forming a resist film, a wafer is repeatedly subjected to a heatingprocess and a cooling process. Thus, the warp of the wafer may be assignificantly large as about several hundred micrometers to onemillimeter.

When a warped wafer is rotating to be processed, a height position ofthe periphery of the wafer may vary. Thus, when the edge rinsing processis performed to the periphery of the wafer, the gap between theperiphery and a nozzle for supplying an organic solvent may vary.Similarly, when the periphery exposing and developing process isperformed to the periphery of the wafer, the optical path length up tothe periphery may vary. Thus, when the periphery removal process (edgerinsing process, periphery exposing and developing process, etc.) isperformed to the warped wafer, the removal width of the peripheralportion of the resist film disadvantageously becomes non-uniform alongthe periphery of the wafer. For example, the removal width may not reacha target value or may exceed the target value. Particularly in recentyears, further miniaturization of the pattern is required to form ahighly-integrated circuit on a wafer. If a wafer has a part whoseremoval width of a peripheral portion of a resist film is large, highintegration of circuits on one substrate is prevented.

SUMMARY OF THE INVENTION

The disclosure describes a substrate processing method, a substrateprocessing apparatus and a computer-readable storage medium capable ofproperly processing a periphery of a substrate even if the substrate iswarped.

A substrate processing method in a first aspect of the presentdisclosure comprises a first step that takes an image of an end face ofa reference substrate, whose warp amount is known, over a wholeperiphery of the reference substrate by means of a camera; a second stepthat performs image processing of the image taken in the first step,thereby to obtain shape data of the end face of the reference substrateover a whole periphery of the reference substrate; a third step thattakes an image of an end face of a process substrate over a wholeperiphery of the process substrate by means of a camera; a fourth stepthat performs image processing of the image taken in the third step,thereby to obtain shape data of the end face of the process substrateover a whole periphery of the process substrate; a fifth step thatcalculates a warp amount of the process substrate based on the shapedata obtained in the second step and the shape data obtained in thefourth step; a sixth step that supplies a coating liquid to a surface ofthe process substrate thereby to form a coating film on the surface ofthe process substrate; a seventh step that determines a supply positionfrom which an organic solvent is to be supplied to a peripheral portionof the coating film, based on the warp amount calculated in the fifthstep, and supplies the organic solvent from the supply position todissolve the peripheral portion of the coating film and remove the samefrom the process substrate.

In the substrate processing method in the first aspect, the fifth stepcalculates a warp amount of the process substrate, and the seventh stepdetermines, based on the warp amount, a supply position from which anorganic solvent is to be supplied to the peripheral portion of thecoating film, and dissolves the peripheral portion by the organicsolvent from the supply position so as to remove the same from theprocess substrate. Thus, since the supply position from which theorganic solvent is to be supplied to the peripheral portion of thecoating film can be properly determined depending on the warp amount ofthe process substrate, the removal width of the peripheral portion canbe made more uniform. As a result, even if the process substrate iswarped, the periphery of the process substrate can be properlyprocessed. In addition, since a circuit can be formed on the surface ofthe process substrate at a portion close to the periphery, highintegration of circuits on the process substrate is promoted whereby theprocess substrate can be more efficiently utilized.

The substrate processing method in the first aspect may further comprisea periphery exposure step that exposes, after the seventh step, thecoating film in the peripheral portion of the surface of the processsubstrate at a predetermined exposure width over the whole periphery ofthe process substrate, wherein in the periphery exposure step theexposure width is determined based on the warp amount calculated in thefifth step. In this case, since the exposure width can be properlydetermined depending on the warp amount of the process substrate, theexposure width of the peripheral portion can be made more uniform. Thus,by developing the process substrate after the peripheral exposure step,the removal width of the peripheral portion can be made more uniform.

The substrate processing method in the first aspect may further comprisean eighth step that heats the coating film after the seventh step; aninth step that takes, after the eighth step, an image of the end faceof the process substrate over the whole periphery of the processsubstrate by means of a camera; a tenth step that performs imageprocessing of the image taken in the ninth step, thereby to obtain shapedata of the end face of the process substrate over the whole peripheryof the process substrate; and an eleventh step that calculates a warpamount of the process substrate based on the shape data obtained in thesecond step and the shape data obtained in the tenth step; wherein themethod does not perform exposure of the process substrate if the warpamount calculated in the eleventh step is greater than a thresholdvalue. In this case, a process substrate that is difficult to be exposedby an exposure apparatus can be discriminated beforehand, so that such aprocess substrate can be excluded from the exposure process. Thus, theprocess efficiency of process substrates can be improved.

The substrate processing method in the first aspect may further comprisean eighth step that heats the coating film after the seventh step; aninth step that takes, after the eighth step, an image of the end faceof the process substrate over the whole periphery of the processsubstrate by means of a camera; a tenth step that performs imageprocessing of the image taken in the ninth step, thereby to obtain shapedata of the end face of the process substrate over the whole peripheryof the process substrate; and an eleventh step that calculates a warpamount of the process substrate based on the shape data obtained in thesecond step and the shape data obtained in the tenth step; a peripheryexposure step that exposes, after the ninth step, the coating film inthe peripheral portion of the surface of the process substrate at apredetermined exposure width over the whole periphery of the processsubstrate, wherein in the periphery exposure step the exposure width isdetermined based on the warp amount calculated in the eleventh step. Inthis case, since the exposure width can be more properly determineddepending on the warp amount of the process substrate that has beensubjected to the heating process in the eighth step, the exposure widthof the peripheral portion can be made more uniform. Thus, by developingthe process substrate after the peripheral exposure step, the removalwidth of the peripheral portion can be made more uniform.

The substrate processing method may omit exposure of the processsubstrate if the warp amount calculated in the eleventh step is greaterthan a threshold value. In this case, a process substrate that isdifficult to be exposed by an exposure apparatus can be discriminatedbeforehand and the process substrate can be excluded from the exposureprocess. Thus, the process efficiency of process substrates can beimproved.

A substrate processing method in a second aspect of the disclosurecomprises: a first step that takes an image of an end face of areference substrate, whose warp amount is known, over a whole peripheryof the reference substrate by means of a camera; a second step thatperforms image processing of the image taken in the first step, therebyto obtain shape data of the end face of the reference substrate over awhole periphery of the reference substrate; a third step that takes animage of an end face of a process substrate over a whole periphery ofthe process substrate by means of a camera; a fourth step that performsimage processing of the image taken in the third step, thereby to obtainshape data of the end face of the process substrate over a wholeperiphery of the process substrate; a fifth step that calculates a warpamount of the process substrate based on the shape data obtained in thesecond step and the shape data obtained in the fourth step; a sixth stepthat supplies a coating liquid to a surface of the process substratethereby to form a coating film on the surface of the process substrate;and a periphery exposure step that exposes the coating film in theperipheral portion of the surface of the process substrate at apredetermined exposure width over the whole periphery of the processsubstrate, wherein in the periphery exposure step the exposure width isdetermined based on the warp amount calculated in the fifth step.

In the substrate processing method in the second aspect, the fifth stepcalculates a warp amount of the process substrate, and in the peripheryexposure step, the exposure width is determined based on the warpamount. Thus, since the exposure width can be determined depending onthe warp amount of the process substrate, the exposure width of theperipheral portion can be made more uniform. Therefore, by developingthe process substrate after the periphery exposure step, the removalwidth of the peripheral portion can be made more uniform. As a result,even if the process substrate is warped, the periphery of the processsubstrate can be properly processed. In addition, since a circuit can beformed on the surface of the process substrate in areas close to theperiphery, higher integration of circuits on the process substrate isachieved whereby the process substrate can be more efficiently utilized.

The substrate processing method in the second aspect may furthercomprise a seventh step that heats the coating film after the sixthstep, wherein the third, fourth and fifth steps are performed after theseventh step. In this case, since the exposure width can be moreproperly determined depending on the warp amount of the processsubstrate that has been subjected to the heating process in the seventhstep, the exposure width of the peripheral portion can be made moreuniform. Thus, by developing the process substrate after the peripheryexposure step, the removal width of the peripheral portion can be mademore uniform.

The substrate processing method may omit exposure of the processsubstrate if the warp amount calculated in the fifth step is greaterthan a threshold value. In this case, a process substrate that isdifficult to be exposed by an exposure apparatus can be discriminatedbeforehand and such a process substrate can be excluded from theexposure process. Thus, the process efficiency of process substrates canbe improved.

The reference substrate may be flat; the shape data obtained in thesecond step may be data on a first profile line passing through a centerof the end face of the reference substrate; the shape data obtained inthe fourth step may be data on a second profile line passing through acenter of the end face of the process substrate; and the fifth step maycalculate the warp amount of the process substrate based on the data onthe first profile line and the data on the second profile line. In thiscase, the warp amount of the process substrate can be more easilycalculated from the data on the first profile line and the data on thesecond profile line.

The substrate processing method in the first or second aspect mayfurther comprise: a peripheral portion imaging step that takes an imageof a peripheral portion of a surface of the process substrate by meansof a camera; and an inspecting step that inspects condition of the endface of the process substrate through image processing of the imagetaken in the fourth step, and inspects condition of the peripheralportion of the surface of the process substrate through image processingof the image taken in the peripheral portion imaging step. In this case,a defect (for example, flaw, crack, scratch, etc.) in the vicinity ofthe periphery of the process substrate can be detected and the processsubstrate can be excluded from the various processes. Thus, the processefficiency of process substrates can be improved.

A substrate processing apparatus in an third aspect of the presentdisclosure comprises: a coating liquid supplying unit configured tosupply a coating liquid onto a surface of a process substrate; a solventsupplying unit configured to supply a first organic solvent and a secondorganic solvent onto a surface of a process substrate; a first rotaryholding unit configured to hold and rotate the process substrate; atleast one camera; and a control unit, wherein the control unit isconfigured to control the substrate processing apparatus to perform aprocedure including: a first step that takes an image of an end face ofa reference substrate, whose warp amount is known, over a wholeperiphery of the reference substrate by means of said at least onecamera; a second step that performs image processing of the image takenin the first step, thereby to obtain shape data of the end face of thereference substrate over a whole periphery of the reference substrate; athird step that takes an image of an end face of a process substrateover a whole periphery of the process substrate by means of said atleast one camera; a fourth step that performs image processing of theimage taken in the third step, thereby to obtain shape data of the endface of the process substrate over a whole periphery of the processsubstrate; a fifth step that calculates a warp amount of the processsubstrate based on the shape data obtained in the second step and theshape data obtained in the fourth step; a sixth step that controls thecoating liquid supplying unit and the first rotary holding unit andsupplies a coating liquid to a surface of the rotating process substratethereby to form a coating film on the surface of the process substrate;a seventh step that controls the solvent supplying unit and the firstrotary holding unit, determines a supply position from which an organicsolvent is to be supplied to a peripheral portion of the coating film,based on the warp amount calculated in the fifth step, and supplies theorganic solvent from the supply position to dissolve the peripheralportion of the coating film and remove the same from the rotatingprocess substrate.

In the substrate processing method in the third aspect, the control unitis configured to control the substrate processing apparatus to perform aprocedure including: the fifth step that calculates a warp amount of theprocess substrate, and the seventh step that determines a supplyposition from which an organic solvent is to be supplied to a peripheralportion of the coating film, based on the warp amount, and supplies theorganic solvent from the supply position to dissolve the peripheralportion of the coating film and remove the same from the rotatingprocess substrate. Since the supply position from which the organicsolvent is to be supplied to a peripheral portion of the coating filmcan be property determined based on the warp amount of the processsubstrate, the removal width of the peripheral portion can be made moreuniform. As a result, even if the process substrate is warped, theperiphery of the process substrate can be properly processed. Inaddition, since circuits can be formed on the surface of the processsubstrate in areas close to the periphery, higher integration ofcircuits on the process substrate is achieved whereby the processsubstrate can be more efficiently utilized.

The substrate processing apparatus in the third aspect may furthercomprise an irradiating unit configured to irradiate a peripheralportion of the surface of the process substrate with energy beam,wherein the control unit is configured to control the irradiating unitto perform a periphery exposure step that exposes, after the seventhstep, the coating film in the peripheral portion of the surface of theprocess substrate at a predetermined exposure width over the wholeperiphery of the process substrate, and wherein in the peripheryexposure step the exposure width is determined based on the warp amountcalculated in the fifth step. In this case, since the exposure width canbe properly determined depending on the warp amount of the processsubstrate, the exposure width of the peripheral portion can be made moreuniform. Thus, by developing the process substrate after the peripheralexposure step, the removal width of the peripheral portion can be mademore uniform.

The substrate processing apparatus in the third aspect may furthercomprise a memory unit that stores information on the process substrate,wherein the control unit is configured to control the substrateprocessing apparatus to perform the procedure further including: aneighth step that heats the coating film after the seventh step; a ninthstep that takes, after the eighth step, an image of the end face of theprocess substrate over the whole periphery of the process substrate bymeans of said at least one camera; a tenth step that performs imageprocessing of the image taken in the ninth step, thereby to obtain shapedata of the end face of the process substrate over the whole peripheryof the process substrate; an eleventh step that calculates a warp amountof the process substrate based on the shape data obtained in the secondstep and the shape data obtained in the tenth step; and a storing stepthat stores in the memory unit information that the process substrateshould not be subjected to an exposure process, if the warp amountcalculated in the eleventh step is greater than a threshold value. Inthis case, a process substrate that is difficult to be exposed by anexposure apparatus can be discriminated beforehand and the processsubstrate can be excluded from the exposure process. Thus, the processefficiency of process substrates can be improved.

The substrate processing apparatus according to the third aspect mayfurther comprise an irradiating unit configured to irradiate aperipheral portion of the surface of the process substrate with energybeam, wherein the control unit is configured to control the substrateprocessing apparatus to perform the procedure further including: aneighth step that heats the coating film after the seventh step; a ninthstep that takes, after the eighth step, an image of the end face of theprocess substrate over the whole periphery of the process substrate bymeans of said at least one camera; a tenth step that performs imageprocessing of the image taken in the ninth step, thereby to obtain shapedata of the end face of the process substrate over the whole peripheryof the process substrate; an eleventh step that calculates a warp amountof the process substrate based on the shape data obtained in the secondstep and the shape data obtained in the tenth step; and a peripheryexposure step that controls, after the ninth step, the irradiating unitand exposes the coating film in the peripheral portion of the surface ofthe process substrate at a predetermined exposure width over the wholeperiphery of the process substrate, and wherein in the peripheryexposure step the exposure width is determined based on the warp amountcalculated in the fifth step. In this case, since the exposure width canbe more properly determined depending on the warp amount of the processsubstrate that has been subjected to the heating process in the eighthstep, the exposure width of the peripheral portion can be made moreuniform. Thus, by developing the process substrate after the peripheralexposure step, the removal width of the peripheral portion can be mademore uniform.

The substrate processing apparatus according to the third aspect mayfurther comprise a memory unit that stores information on the processsubstrate, wherein the control unit is configured to control thesubstrate processing apparatus to perform the procedure furtherincluding: a storing step that stores in the memory unit informationthat the process substrate should not be subjected to an exposureprocess, if the warp amount calculated in the eleventh step is greaterthan a threshold value. In this case, a process substrate that isdifficult to be exposed by an exposure apparatus can be discriminatedbeforehand and the process substrate can be excluded from the exposureprocess. Thus, the process efficiency of process substrates can beimproved.

A substrate processing apparatus in a fourth aspect of the presentdisclosure comprises: a coating liquid supplying unit configured tosupply a coating liquid onto a surface of a process substrate; anirradiating unit configured to irradiate a peripheral portion of thesurface of the process substrate with energy beam; at least one camera;and a control unit, wherein the control unit is configured to controlthe substrate processing apparatus to perform a procedure including: afirst step that takes an image of an end face of a reference substrate,whose warp amount is known, over a whole periphery of the referencesubstrate by means of said at least one camera; a second step thatperforms image processing of the image taken in the first step, therebyto obtain shape data of the end face of the reference substrate over awhole periphery of the reference substrate; a third step that takes animage of an end face of a process substrate over a whole periphery ofthe process substrate by means of said at least one camera; a fourthstep that performs image processing of the image taken in the thirdstep, thereby to obtain shape data of the end face of the processsubstrate over a whole periphery of the process substrate; a fifth stepthat calculates a warp amount of the process substrate based on theshape data obtained in the second step and the shape data obtained inthe fourth step; a sixth step that controls the coating liquid supplyingunit and supplies a coating liquid to a surface of the process substratethereby to form a coating film on the surface of the process substrate;a periphery exposure step that controls, after the sixth step, theirradiating unit and exposes the coating film in the peripheral portionof the surface of the process substrate at a predetermined exposurewidth over the whole periphery of the process substrate, and wherein inthe periphery exposure step the exposure width is determined based onthe warp amount calculated in the fifth step.

In the substrate processing apparatus in the fourth aspect, control unitis configured to control the substrate processing apparatus to perform aprocedure including: the fifth step that calculates a warp amount of theprocess substrate, and the periphery exposure step that determines theexposure width based on the warp amount. Since the exposure width can beproperty determined based on the warp amount of the process substrate,the exposure width of the peripheral portion can be made more uniform.Thus, by developing the process substrate after the peripheral exposurestep, the removal width of the peripheral portion can be made moreuniform. As a result, even if the process substrate is warped, theperiphery of the process substrate can be properly processed. Inaddition, since circuits can be formed on the surface of the processsubstrate at areas close to the periphery, higher integration ofcircuits on the process substrate is promoted whereby the processsubstrate can be more efficiently utilized.

The substrate processing apparatus in the fourth aspect may furthercomprise a heating unit configured to heat the process substrate,wherein the control unit is configured to control the substrateprocessing apparatus to perform the procedure further including: aseventh step that heats, after the sixth step, the coating unit by meansof the heating unit, wherein the third, fourth and fifth steps areperformed after the seventh step. In this case, since the exposure widthcan be more properly determined based on on the warp amount of theprocess substrate that has been subjected to the heating process in theseventh step, the exposure width of the peripheral portion can be mademore uniform. Thus, by developing the process substrate after theperiphery exposure step, the removal width of the peripheral portion canbe made more uniform.

The substrate processing apparatus in the fourth aspect may furthercomprise a memory unit that stores information on the process substrate,wherein the control unit is configured to control the substrateprocessing apparatus to perform the procedure further including: astoring step that stores in the memory unit information that the processsubstrate should not be subjected to an exposure process, if the warpamount calculated in the fifth step is greater than a threshold value.In this case, a process substrate that is difficult to be exposed by anexposure apparatus can be discriminated beforehand and the processsubstrate can be excluded from the exposure process. Thus, the processefficiency of process substrates can be improved.

The substrate processing apparatus in the fourth aspect may furthercomprise a second rotary holding unit configured to hold and rotate theprocess substrate, wherein the control unit is configured to control thesecond rotary holding unit to rotate the process substrate in the thirdstep, and wherein during rotation of the process substrate the image ofthe end face of the process substrate over the whole periphery of theprocess substrate is taken by means of said at least one camera in thethird step, and wherein parts of the first rotary holding unit forholding the process substrate have the same size as parts of the secondrotary holding unit for holding the process substrate. When the rotaryholding unit holds a process substrate, stresses are induced in partsbetween the rotary holding unit and the process substrate so that thewarp amount of the process substrate may vary. As described above, whenthe parts of the first rotary holding unit for holding the processsubstrate have the same size as the parts of the second rotary holdingunit for holding the process substrate, stresses induced in the partsbetween the respective rotary holding units and the process substrateare substantially the same. Thus, variation of the warp amount when thethird, fourth and fifth steps calculate the warp amount of a processsubstrate, and variation of the warp amount when the seventh step thatsupplies the organic solvent to the peripheral portion of the coatingfilm are substantially the same. Thus, in the seventh step, the supplyposition from which an organic solvent is to be supplied to theperipheral portion of the coating film can be easily determined.

The substrate processing apparatus in the fourth aspect may furthercomprise first and second rotary holding unit each configured to holdand rotate the process substrate, wherein the control unit is configuredto control the first rotary holding unit to rotate the process substratein the third step, and wherein during rotation of the process substratethe image of the end face of the process substrate over the wholeperiphery of the process substrate is taken by means of said at leastone camera in the third step, wherein the control unit is configured tocontrol the second rotary holding unit to rotate the process substratein the periphery exposure step, and wherein during rotation of theprocess substrate the coating film in the peripheral portion of thesurface of the process substrate is exposed at a predetermined exposurewidth over the whole periphery of the process substrate, and whereinparts of the first rotary holding unit for holding the process substratehave the same size as parts of the second rotary holding unit forholding the process substrate. When the rotary holding unit holds aprocess substrate, stresses are induced in parts between the rotaryholding unit and the process substrate so that the warp amount of theprocess substrate may vary. As described above, when the parts of thefirst rotary holding unit for holding the process substrate have thesame size as the parts of the second rotary holding unit for holding theprocess substrate, stresses induced in the parts between the respectiverotary holding units and the process substrate are substantially thesame. Thus, variation of the warp amount when the third, fourth andfifth steps calculate the warp amount of a process substrate, andvariation of the warp amount when the periphery exposure step exposesthe peripheral portion of the coating film are substantially the same.Thus, in the periphery exposure step, the exposure width of theperipheral portion of the coating film can be easily determined.

A first processing chamber in which the third step that takes the imageof the process substrate is performed, may be different from a secondprocessing chamber in which the tenth step that takes the image of theprocess substrate is performed.

The substrate processing apparatus in the fourth aspect may furthercomprise a second rotary holding unit configured to hold and rotate theprocess substrate; and a mirror member having a reflecting surface thatopposes an end face of the substrate and a peripheral portion of a backsurface of the substrate held by the second rotary holding unit, thereflecting surface being inclined with respect to a rotation axis of therotary holding unit; wherein one of said at least one camera has animaging device that receives both first light and second light through alens, the first light coming from a peripheral portion of a frontsurface of the substrate held by the second rotary holding unit, and thesecond light being a reflected light of second light which comes fromthe end face of the substrate held by the second rotary holding unit andis reflected by the reflecting surface. In this case, both theperipheral portion of the front surface of the process substrate and theend face of the substrate can be simultaneously imaged by the onecamera. Thus, since a plurality of cameras are no longer necessary, aspace for installation of these cameras is unneeded. In addition, sincea mechanism for moving the camera is unnecessary, a space forinstallation of the mechanism is unneeded. Therefore, the imaging unitcan achieve reduction in size and decrease in cost.

The reference substrate may be flat; the control unit may be configuredto control the substrate processing apparatus such that: the second stepobtains, as the shape data of the end face of the reference substrate,data on a first profile line passing through a center of the end face ofthe reference substrate; the fourth step obtains, as the shape data ofthe end face of the process substrate, data on a second profile linepassing through a center of the end face of the process substrate; andthe fifth step calculates the warp amount of the process substrate basedon the data on the first profile line and the data on the second profileline. In this case, the warp amount of the process substrate can be moreeasily calculated from the data on the first profile line and the dataon the second profile line.

The control unit may be configured to control the substrate processingapparatus to perform the procedure further including: a peripheralportion imaging step that takes an image of a peripheral portion of asurface of the process substrate by means of said at least one camera;and an inspecting step that inspects condition of the end face of theprocess substrate through image processing of the image taken in thefourth step, and inspects condition of the peripheral portion of theprocess substrate through image processing of the image taken in theperipheral portion imaging step. In this case, a defect (for example,flaw, crack, scratch, etc.) in the vicinity of the periphery of theprocess substrate can be detected and the process substrate can beexcluded from the various processes. Thus, the process efficiency ofprocess substrates can be improved.

A computer-readable storage medium in the fifth aspect of the presentdisclosure stores a program that makes a substrate processing apparatusexecute the aforementioned substrate processing method. Similarly to theabove-described substrate processing method, the computer-readablestorage medium according to the other aspect of the present disclosureis capable of making more uniform the removal width of the peripheralportion of the coating film. In this specification, thecomputer-readable storage medium includes a non-transitory tangiblemedium (non-transitory computer storage medium) (e.g., various mainstorage apparatus or an auxiliary storage apparatus), and a propagationsignal (transitory computer storage medium) (e.g., data signal that canbe provided through a network).

The substrate processing method, the substrate processing apparatus andthe computer-readable storage medium according to the above can properlyperform process to the periphery of a substrate, even if the substrateis warped.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a substrate processing system.

FIG. 2 is a sectional view taken along the II-II line in FIG. 1.

FIG. 3 is a plan view showing unit processing blocks (BCT block, HMCTblock, COT block and DEV block).

FIG. 4 is a plan view showing the unit processing block (COT block).

FIG. 5 is a schematic view showing a liquid processing unit.

FIG. 6 is a cross sectional view of an inspection unit seen from above.

FIG. 7 is a cross sectional view of the inspection unit seen from thelateral side.

FIG. 8 is a perspective view showing the inspection unit.

FIG. 9 is a perspective view of a periphery imaging subunit seen fromthe front side.

FIG. 10 is a perspective view of the periphery imaging subunit seen frombehind.

FIG. 11 is a plan view of the periphery imaging subunit.

FIG. 12 is a side view of a two-surface imaging module.

FIG. 13 is a perspective view showing a mirror member.

FIG. 14 is a side view showing the mirror member.

FIG. 15A is a diagram for explaining a condition where light from anilluminating module is reflected by the mirror member.

FIG. 15B is a diagram for explaining a condition where light from awafer is reflected by the mirror member.

FIG. 16 is a side view of a back-surface imaging subunit.

FIG. 17 is a cross sectional view of a periphery exposure unit seen fromthe lateral side.

FIG. 18 is a perspective view showing the periphery exposure unit.

FIG. 19 is a block diagram showing a main part of the substrateprocessing system.

FIG. 20 is a schematic view showing a hardware structure of acontroller.

FIG. 21 is a flowchart for explaining a procedure for calculating aprofile line of a reference wafer

FIG. 22 is a flowchart for explaining an example (first example) of awafer processing procedure.

FIG. 23 is a flowchart for explaining a wafer inspection procedure.

FIG. 24A is a graph showing a relationship between a warp amount of awafer and a removal width of a peripheral portion of a resist film.

FIG. 24B is a diagram for explaining the removal width of the peripheralportion of the resist film.

FIG. 25 is a graph showing profile lines of a wafer and a referencewafer.

FIG. 26 is a graph showing a warp amount.

FIG. 27A is a perspective view showing a wafer having a hyperbolicparaboloid shape.

FIG. 27B is a perspective view showing a wafer having an upwardly convexparaboloid of revolution shape.

FIG. 27C is a perspective view showing a wafer having a downwardlyconvex paraboloid of revolution shape.

FIG. 28 is a flowchart for explaining another example (second example)of the wafer processing procedure.

FIG. 29 is a flowchart for explaining yet another example (thirdexample) of the wafer processing procedure.

DETAILED DESCRIPTION OF THE INVENTION

It should be firstly noted that the present invention is not limited tothe below-described illustrative embodiments. In the below-describeddescription, the same element or an element having the same function aredesignated by the same reference symbol, and overlapping description isomitted.

Substrate Processing System

As shown in FIG. 1, a substrate processing system 1 (substrateprocessing apparatus) includes a coating and developing apparatus 2(substrate processing apparatus) and a controller 10 (control unit). Thesubstrate processing system 1 is equipped with an exposure apparatus 3.The exposure apparatus 3 has a controller (not shown) capable ofcommunicating with the controller 10 of the substrate processing system1. The exposure apparatus 3 is configured to send and receive a wafer W(substrate) to and from the coating and developing apparatus 2, and toperform an exposure process (pattern exposure) of a photosensitiveresist film formed on a front surface Wa of a wafer W (see FIG. 5). Tobe specific, a part to be exposed of the photosensitive resist film(photosensitive coating film) is selectively irradiated with an energyray using a suitable method such as liquid immersion exposure. Theenergy ray may be, for example, ArF excimer laser, KrF excimer laser,g-ray, i-ray or EUV (Extreme Ultraviolet) ray.

Before the exposure process by the exposure apparatus 3, the coating anddeveloping apparatus 2 performs a process for forming a photosensitiveresist film or a non-photosensitive resist film (collectively referredto as “resist film R” herebelow (see FIG. 5)) on the front surface Wa ofthe wafer W. After the exposure process by the exposure apparatus 3, thecoating and developing apparatus 2 performs a process for developing theexposed photosensitive resist film.

The wafer W may have a circular plate shape or may have a plate shapeother than the circular shape such as a polygonal shape. The wafer W mayhave a cutout formed by partially cutting out the wafer W. The cutoutmay be, for example, a notch (U-shape or V-shaped groove) or a linearlyextending part (so-called orientation flat). The wafer W may be, forexample, a semiconductor substrate, a glass substrate, a mask substrate,an FPD (Flat Panel Display) substrate, or other various substrates. Adiameter of the wafer W may be, for example, about 200 mm to 450 mm.When an edge of the wafer W is beveled (chamfered), the “front surface”in this specification includes the beveled part when seen from the sideof the front surface Wa of the wafer W. Similarly, a “back surface” inthis specification includes a beveled part when seen from the side of aback surface Wb of the wafer W (see FIG. 5). An “end face” in thisspecification includes a beveled part when seen from the side of an endface We of the wafer W (see FIG. 5).

As shown in FIGS. 1 to 4, the coating and developing apparatus 2includes a carrier block 4, a processing block 5 and an interface block6. The carrier block 4, the processing block 5 and the interface block 6are horizontally aligned.

As shown in FIGS. 1, 3 and 4, the carrier block 4 includes a carrierstation 12 and a loading and unloading unit 13. The carrier station 12supports thereon a plurality of carriers 11. Each carrier 11 cansealingly contain at least one wafer W. A side surface 11 a of thecarrier 11 is provided with an opening and closing door (not shown)through which a wafer W is taken into and out from the carrier 11. Thecarrier 11 is detachably installed on the carrier station 12 such thatthe side surface 11 a faces the loading and unloading unit 13.

A storage medium 11 b is disposed in the carrier 11 (see FIG. 1). Thestorage medium 11 b is, for example, a non-volatile memory, and storesinformation on respective wafers W in the carrier 11 (described later indetail). When the carrier 11 is mounted on the carrier station 12, thecontroller 10 can access the storage medium 11 b, so that informationstored in the storage medium 11 b can be read out, and that informationcan be written in the storage medium 11 b.

The loading and unloading unit 13 is positioned between the carrierstation 12 and the processing block 5. The loading and unloading unit 13has a plurality of opening and closing doors 13 a. When the carrier 11is placed on the carrier station 12, the opening and closing door of thecarrier 11 faces the opening and closing door 13 a. By simultaneouslyopening the opening and closing door 13 a and the opening and closingdoor in the side surface 11 a, the inside of the carrier 11 and theinside of the loading and unloading unit 13 communicate with each other.The loading and unloading unit 13 incorporates a delivery arm A1. Thedeliver arm A1 takes a wafer W out from the carrier 11 and delivers itto the processing block 5, as well as receives a wafer W from theprocessing block 5 and returns it into the carrier 11.

As shown in FIGS. 1 and 2, the processing block 5 has unit processingblocks 14 to 17. The unit processing blocks 14 to 17 are arranged suchthat the unit processing block 17, the unit processing block 14, theunit processing block 15 and the unit processing block 16 are aligned inthis order from the floor surface side. As shown in FIG. 3, each of theunit processing blocks 14, 15 and 17 has a liquid processing unit U1, athermal processing unit U2 (heating unit) and an inspection unit U3. Asshown in FIG. 4, the unit processing block 16 has a liquid processingunit U1, a thermal processing unit U2 (heating unit), an inspection unitU3 and a periphery exposure unit U4.

The liquid processing unit U1 is configured to supply various processliquids to a front surface Wa of a wafer W (described later in detail).The thermal processing unit U2 is configured to perform a thermalprocess by heating a wafer W by, e.g., a heat plate and cooling theheated wafer W by, e.g., a cooling plate. The inspection unit U3 isconfigured to inspect respective surfaces (front surface Wa, backsurface Wb and end face Wc) of a wafer W (described later in detail).The periphery exposure unit U4 is configured to irradiate a peripheralportion Wd (see FIG. 5) of a wafer W on which a resist film R is formedwith ultraviolet ray so as to expose the resist film R on the peripheralportion Wd.

The unit processing block 14 is a lower film forming block (BCT block)configured to form a lower film on a front surface Wa of a wafer W. Theunit processing block 14 incorporates a transfer arm A2 that transfers awafer W to the respective units U1 to U3 (see FIGS. 2 and 3). The liquidprocessing unit U1 of the unit processing block 14 forms a coating filmby coating a front surface Wa of a wafer W with a coating liquid forforming the lower film. The thermal processing unit U2 of the unitprocessing block 14 performs various thermal processes for forming thelower film. A concrete example of the thermal processes may be a heatingprocess for hardening the coating film into the lower film. The lowerfilm may be an antireflection (SiARC) film, for example.

The unit processing block 15 is an intermediate film (hard mask) formingblock (HMCT block) configured to form an intermediate film on the lowerfilm. The unit processing block 15 incorporates a transfer arm A3 thattransports a wafer W to the respective units U1 to U3 (see FIGS. 2 and3). The liquid processing unit U1 of the unit processing block 15 formsa coating film by coating the lower film with a coating liquid forforming the intermediate film. The thermal processing unit U2 of theunit processing block 15 performs various thermal processes for formingthe intermediate film. A concrete example of the thermal processes maybe a heating process for hardening the coating film into theintermediate film. The intermediate film may be an SOC (Spin On Carbon)film or an amorphous carbon film, for example.

The unit processing block 16 is a resist-film forming block (COT block)configured to form a thermosetting resist film on the intermediate film.The unit processing block 16 incorporates a transfer arm A4 thattransfers a wafer W to the respective units U1 to U3 (see FIGS. 2 and4). The liquid processing unit U1 of the unit processing block 16 formsa coating film by coating the intermediate film with a coating liquid(resist agent) for forming a resist film. The thermal processing unit U2of the unit processing block 16 performs various thermal processes forforming the resist film. A concrete example of the thermal processes maybe a heating process (PAB: Pre Applied Bake) for hardening the coatingfilm into the resist film R.

The unit processing block 17 is a developing block (DEV block)configured to develop the exposed resist film R. The unit processingblock 17 incorporates a transfer arm A5 that transfers a wafer W to therespective units U1 to U3, and a direct transfer arm A6 that transfers awafer W without passing through these units (see FIGS. 2 and 3). Theliquid processing unit U1 of the unit processing block 17 develops theexposed resist film R by supplying a developer to the resist film R. Theliquid processing unit U1 of the unit processing block 17 supplies arinse liquid to the developed resist film R so as to rinse awaydissolved components of the resist film together with the developer.Thus, the resist film R is partly removed, so that a resist pattern isformed. The thermal processing unit U2 of the unit processing block 17performs various thermal processes for the developing process. Aconcrete example of the thermal processes may be a heating processbefore the developing process (PEB: Post Exposure Bake), a heatingprocess after the developing process (PB: Post Bake) and the like.

As shown in FIGS. 2 to 4, a shelf unit U10 is disposed in the processingblock 5 on the side of the carrier block 4. The shelf unit U10 extendsfrom the floor surface to the unit processing block 16, and is dividedinto a plurality of cells aligned in the vertical direction. Anelevation arm A7 is provided near the shelf unit U10. The elevation armA7 moves a wafer W up and down among the cells of the shelf unit U10.

A shelf unit U11 is disposed in the processing block 5 on the side ofthe interface block 6. The shelf unit extends from the floor surface toan upper part of the unit processing block 17, and is divided into aplurality of cells aligned in the vertical direction.

The interface block 6 incorporates a delivery arm A8, and is connectedto the exposure apparatus 3. The delivery arm A8 is configured to take awafer W from the shelf unit U11 and deliver it to the exposure apparatus3, and is configured to receive a wafer W from the exposure apparatus 3and return it to the shelf unit U11.

The controller 10 controls the substrate processing system 1 partly orentirely. Details of the controller 10 will be described later. Thecontroller 10 can send and receive a signal to and from the controllerof the exposure apparatus 3. Due to the cooperation of the respectivecontrollers, the substrate processing system 1 and the exposureapparatus 3 are controlled.

Structure of Liquid Processing Unit

Next, the liquid processing unit U1 is described in more detail withreference to FIG. 5. As shown in FIG. 5, the liquid processing unit U1includes a rotary holding unit 20, a liquid supplying unit 30 (coatingliquid supplying unit) and a liquid supplying unit 40 (solvent supplyingunit).

The rotary holding unit 20 has a rotating unit 21 and a holding unit 22.The rotating unit 21 has a shaft 23 projecting therefrom upward. Therotating unit 21 rotates the shaft 23 by, e.g., an electric motor as apower source. The holding unit 22 is disposed on a distal end of theshaft 23. A wafer W is placed on the holding unit 22. The holding unit22 is, for example, a suction chuck that substantially horizontallyholds a wafer W by suction. The shape of the holding unit 22 (suctionchuck) is not specifically limited, and may be circular, for example.The size of the holding unit 22 may be smaller than a wafer W. If theholding unit 22 has a circular shape, the holding unit 22 may have asize of about 80 mm in diameter, for example.

The rotary holding unit 20 rotates the wafer W about an axis (rotationaxis) that is perpendicular to a front surface Wa of the wafer W, whenthe the posture of the wafer W is substantially horizontal. In thisembodiment, since the rotation axis passes through the center of thecircular wafer W, the rotation axis is also a center axis. In thisembodiment, as shown in FIG. 5, the rotary holding unit 20 rotates thewafer W clockwise when seen from above.

The liquid supplying unit 30 is configured to supply a process liquid L1onto the front surface Wa of the wafer W. In each of the unit processingblocks 14 to 16, the process liquid L1 is a coating liquid for forming alower film, an intermediate film or a resist film. In this case, theliquid supplying unit 30 functions as a coating liquid supplying unit.In the unit processing block 17, the process liquid is a developer. Inthis case, the liquid supplying unit 30 functions as a developersupplying unit.

The liquid supplying unit 30 includes a liquid source 31, a pump 32, avalve 33, a nozzle 34 and a pipe 35. The liquid source 31 functions as asupplying source of the process liquid L1. The pump 32 pumps the processliquid L1 from the liquid source 31 into the nozzle 34 through the pipe35 and the valve 33. The nozzle 34 is disposed above the wafer W suchthat its discharge port is directed toward the front surface Wa of thewafer W. The nozzle 34 is configured to be movable in the horizontaldirection and in the vertical direction by a drive unit, not shown. Thenozzle 34 can discharge the process liquid L1 pumped from the pump 32onto the front surface Wa of the wafer W. The pipe 35 connects theliquid source 31, the pump 32, the valve 33 and the nozzle 34 in thisorder from the upstream side.

The liquid supplying unit 40 is configured to supply a process liquid L2onto the front surface Wa of the wafer W. In each of the unit processingblocks 14 to 16, the process liquid L2 is an organic solvent forremoving a lower film, an intermediate film or a resist film from thewafer W. In this case, the liquid supplying unit 40 functions as asolvent supplying unit. In the unit processing block 17, the processliquid L2 is a rinse liquid. In this case, the liquid supplying unit 40functions as a rinse liquid supplying unit.

The liquid supplying unit 40 includes a liquid source 41, a pump 42, avalve 43, a nozzle 44 and a pipe 45. The liquid source 41 functions as asupplying source of the process liquid L2. The pump 42 pumps the processliquid L2 from the liquid source 41 into the nozzle 44 through the pipe45 and the valve 43. The nozzle 44 is disposed above the wafer W suchthat its discharge port is directed toward the front surface Wa of thewafer W. The nozzle 44 is configured to be movable in the horizontaldirection and in the vertical direction by a drive unit, not shown. Thenozzle 44 can discharge the process liquid L2 pumped from the pump 42onto the front surface Wa of the wafer W. The pipe 45 connects theliquid source 41, the pump 42, the valve 43 and the nozzle 44 in thisorder from the upstream side.

Structure of Inspection Unit

Next, the inspection unit U3 is described in more detail with referenceto FIGS. 6 to 16. As shown in FIGS. 6 to 8, the inspection unit U3includes a housing 100, a rotary holding subunit 200 (rotary holdingunit), a front surface imaging subunit 300, a periphery imaging subunit400 (substrate imaging apparatus) and a back surface imaging subunit500. The respective subunits 200 to 500 are accommodated in the housing100. A loading and unloading port 101 is formed in one end wall of thehousing 100, through which a wafer W is loaded to the inside of thehousing 100 and unloaded to the outside of the housing 100.

The rotary holding subunit 200 includes a holding table 201, actuators202, 203 and a guide rail 204. The holding table 201 is structured as asuction chuck that substantially horizontally holds a wafer W bysuction, for example. The shape of the holding table 201 (suction chuck)is not limited, and may be circular, for example. The size of theholding table 201 may be smaller than a wafer W, or may be substantiallythe same as that of the holding unit 22 (suction chuck). If the holdingtable 201 has a circular shape, the holding table 201 (suction chuck)may have a size of about 80 mm in diameter, for example.

The actuator 202 is, e.g., an electric motor that drives the holdingtable 201 in rotation. Namely, the actuator 202 rotates a wafer W heldon the holding table 201. The actuator 202 may include an encoder fordetecting a rotating position of the holding table 201. In this case,positions of the respective surfaces of a wafer W to be imaged by therespective imaging subunits 300, 400, 500 and the rotating position canbe related to each other. If a wafer W has a cutout, the posture of thewafer W can be specified based on the cutout recognized by therespective imaging subunits 300, 400, 500, and the rotating positiondetected by the encoder.

The actuator 203 is, e.g., a linear actuator that moves the holdingtable 201 along the guide rail 204. Namely, the actuator 203 allows awafer W held on the holding table 201 to be transferred between one endand the other end of the guide rail 204. Thus, the wafer W held on theholding table 201 can be moved between a first position near the inletand outlet port 101, and a second position near the periphery imagingsubunit 400 and the back surface imaging subunit 500. The guide rail 204extends linearly (e.g., like a straight line) in the housing 100.

The front surface imaging subunit 300 includes a camera 310 (imagingmeans) and an illuminating module 320. The camera 310 and theilluminating module 320 constitute a set of imaging modules. The camera310 includes a lens and one imaging device (e.g., CCD image sensor, CMOSimage sensor, etc.). The camera 310 opposes the illuminating module 320(illuminating unit).

The illuminating module 320 includes a half mirror 321 and a lightsource 322. The half mirror 321 is disposed in the housing 100 such thatit is inclined at substantially 45° with respect to the horizontaldirection. The half mirror 321 is located above an intermediate portionof the guide rail 204 such that the half mirror 321 intersects the guiderail 204 when viewed from above. The half mirror 321 has a rectangularshape. The length of the half mirror 321 is larger than the diameter ofa wafer W.

The light source 322 is located above the half mirror 321. The lightsource 322 is longer than the half mirror 321. Light emitted from thelight source 322 passes through the whole half mirror 321 to traveldownward (toward the guide rail 204). The light having passed throughthe half mirror 321 is reflected by an object located below the halfmirror 321, and is again reflected by the half mirror 321. The lightpasses through the lens of the camera 310 and enters the imaging deviceof the camera 310. Namely, the camera 310 can take an image of an objectpresent in an irradiation area of the light source 322 through the halfmirror 321. For example, when the holding table 201 holding a wafer W ismoved by the actuator 203 along the guide rail 204, the camera 310 cantake an image of the front surface Wa of the wafer W which passesthrough the irradiation area of the light source 322. Data of the imagetaken by the camera 310 is transmitted to the controller 10.

As shown in FIGS. 6 to 12, the periphery imaging subunit 400 includes acamera 410 (imaging means), an illuminating module 420 and a mirrormember 430. The camera 410, the illuminating module 420 (illuminatingunit) and the mirror member 430 constitute a set of imaging modules. Thecamera 410 includes a lens 411 and one imaging device 412 (e.g., CCDimage sensor, CMOS image sensor, etc.). The camera 410 opposes theilluminating module 420.

As shown in FIGS. 9 to 12, the illuminating module 420 is located abovethe wafer W held on the holding table 201. The illuminating module 420includes a light source 421, a light scattering member 422 and a holdingmember 423. The light source 421 may be composed of, for example, aplurality of LED point light sources 421 b (see FIG. 12), for example.

As shown in FIGS. 9 to 12, the holding member 423 holds therein a halfmirror 424, a cylindrical lens 425, a light diffusing member 426, andfocus adjusting lens 427. As shown in FIG. 12, the half mirror 424 isdisposed on an intersection part of the through-hole 423 a and theintersection hole 423 b such that the half mirror 424 is inclined atsubstantially 45° with respect to the horizontal direction. The halfmirror 424 has a rectangular shape.

As shown in FIGS. 9 and 10, the focus adjusting lens 427 is disposed inthe intersection hole 423 b. As long as the focus adjusting lens 427 isa lens having a function for varying a synthetic focal length withrespect to the lens 411, the configuration of the focus adjusting lens427 is not limited. The focus adjusting lens 427 may be a lens having aparallelepiped shape, for example.

As shown in FIGS. 9 and 12, the mirror member 430 is disposed below theilluminating module 420. As shown in FIGS. 9 and 12 to 14, the mirrormember 430 includes a body 431 and a reflecting surface 432. The body431 is made of an aluminum block.

As shown in FIGS. 9 and 14, when a wafer W held by the holding table 201is located at the second position, the reflecting surface 432 opposes anend face Wc of the wafer W and a peripheral portion Wd of a back surfaceWb of the wafer W. The reflecting surface 432 is inclined with respectto the rotary axis of the holding table 201. The reflecting surface 432is mirror finished. For example, a mirror sheet may be attached to thereflecting surface 432. Alternatively, an aluminum plating may beprovided to the reflecting surface 432, or an aluminum material may bevapor-deposited on the reflecting surface 432.

The reflecting surface 432 is a curved surface that is recessed awayfrom the end face Wc of the wafer W held on the holding table 201.Namely, the mirror member 430 is a concave mirror. Thus, a mirror imageof the end face Wc of the wafer W reflected on the reflecting surface432 is enlarged. A radius of curvature of the reflecting surface 432 maybe about 10 mm to 30 mm, for example. A divergence angle θ (see FIG. 14)of the reflecting surface 432 may be about 100° to 150°. The divergenceangle θ of the reflecting surface 432 herein means an angle defined bytwo planes circumscribing the reflecting surface 432.

In the illuminating module 420, light emitted from the light source 421is scattered by the light scattering member 422, enlarged by thecylindrical lens 425, and diffused by the light diffusing member 426.Thereafter, the light passes through the whole half mirror 424 to traveldownward. The diffused light having passed through the half mirror 424is reflected by the reflecting surface 432 of the mirror member 430located below the half mirror 424. When a wafer W held on the holdingtable 201 is located at the second position as shown in FIGS. 13 and15A, the diffused light having been reflected by the reflecting surface432 mainly reaches the end face Wc of the wafer W (if the periphery ofthe wafer W has a beveled part, particularly an upper end of the beveledpart) and the peripheral portion Wd of the front surface Wa.

The light having been reflected from the peripheral portion Wd of thefront surface Wa of the wafer W is not directed toward the reflectingsurface 432 of the mirror member 430 but is reflected again by the halfmirror 424 (see FIG. 15B). The light then passes through the lens 411 ofthe camera 410 to enter the imaging device 412 of the camera 410,without passing through the focus adjusting lens 427. On the other hand,the light having been reflected from the end face Wc of the wafer W isreflected sequentially by the reflecting surface 432 of the mirrormember 430 and the half mirror 424. The light then passes sequentiallythrough the focus adjusting lens 427 and the lens 411 of the camera 410to enter the imaging device 412 of the camera 410. Thus, the opticalpath length of the light coming from the end face Wc of the wafer W tofall on the imaging device 412 of the camera 410 is longer than theoptical path length of the light coming from the peripheral portion Wdof the front surface Wa of the wafer W to fall on the imaging device 412of the camera 410. The optical path difference between these opticalpaths may be about 1 mm to 10 mm, for example. Thus, the imaging device412 of the camera 410 receives both the light which comes from theperipheral portion Wd of the front surface Wa of the wafer W and thelight which comes from the end face Wc of the wafer W. Namely, when thewafer W held by the holding table 201 is located at the second position,the camera 410 can image both the peripheral portion Wd of the frontsurface Wa of the wafer W and the end face Wc of the wafer W. Data ofthe images taken by the camera 410 are transmitted to the controller 10.

If the peripheral portion Wd of the front surface Wa of the wafer W isfocused without the existence of the focus adjusting lens 427, the imageof the peripheral portion Wd of the front surface Wa of the wafer Wtaken by the camera 410 is clear, but the image of the end face Wc ofthe wafer W taken by the camera 410 is likely to be unclear, because ofthe optical path difference. On the other hand, if the end face of thewafer W is focused without the existence of the focus adjusting lens427, the image of the end face Wc of the wafer W is clear, but the imageof the peripheral portion Wd of the front surface Wa of the wafer Wtaken by the camera 410 is likely to be unclear, because of the opticalpath difference. However, since there actually exists the focusadjusting lens 427 in the optical path of the light extending from thereflecting surface 432 of the mirror member 430 to the lens 411, animage forming position, at which an image of the end face Wc of thewafer W is formed, can be adjusted onto the imaging device 412, eventhough there is the optical path difference. Thus, both the images ofthe peripheral portion Wd of the front surface Wa of the wafer W and theend face We of the wafer W, which were imaged by the camera 410, areclear.

As shown in FIGS. 6 to 11 and 16, the back surface imaging subunit 500includes a camera 510 (imaging means) and an illuminating module 520(illuminating unit). The camera 510 and the illuminating module 520constitute a set of imaging modules. The camera 510 includes a lens 511and one imaging device 512 (e.g., CCD image sensor, CMOS image sensor,etc.). The camera 510 opposes the illuminating module 520 (illuminatingunit).

The illuminating module 520 is located below the illuminating module420, and below the wafer W held by the holding table 201. As shown inFIG. 16, the illuminating module 520 includes a half mirror 521 and alight source 522. The half mirror 521 is inclined at substantially 45°with respect to the horizontal direction. The half mirror 521 has arectangular shape.

The light source 522 is located below the half mirror 521. The lightsource 522 is longer than the half mirror 521. Light emitted from thelight source 522 passes through the whole half mirror 521 to travelupward. The light having passed through the half mirror 521 is reflectedby an object located above the half mirror 521, and is again reflectedby the half mirror 521. Then, the light passes through the lens 511 ofthe camera 510 to enter the imaging device 512 of the camera 510.Namely, the camera 510 can image an object present in an irradiationarea of the light source 522 through the half mirror 521. For example,when the wafer W held by the holding table 201 is located at the secondposition, the camera 510 can image the back surface Wb of the wafer W.Data of the image imaged by the camera 510 are transmitted to thecontroller 10.

Structure of Periphery Exposure Unit

Next, the periphery exposure unit U4 is described in more detail withreference to FIGS. 17 and 18. As shown in FIG. 17, the peripheryexposure unit U4 includes a housing 600, a rotary holding subunit 700(rotary holding unit) and an exposure subunit 800 (irradiating unit).The subunits 700 and 800 are disposed in the housing 600. A loading andunloading port 601 is formed in one end wall of the housing 600, throughwhich a wafer W is loaded to the inside of the housing 600 and unloadedto the outside of the housing 600.

As shown in FIGS. 17 and 18, the rotary holding subunit 700 includes aholding table 701, actuators 702, 703 and a guide rail 704. The holdingtable 701 is structured as a suction chuck that substantiallyhorizontally holds a wafer W by suction, for example. The shape of theholding table 701 (suction chuck) is not limited, and may be circular,for example. The size of the holding table 701 may be smaller than thewafer W, and may be substantially the same as those of the holding unit22 (suction chuck) and the holding table 201 (suction chuck). If theholding table 701 has a circular shape, the holding table 701 (suctionchuck) may have a size of about 80 mm in diameter, for example.

The actuator 702 is, e.g., an electric motor that drives the holdingtable 701 in rotation. Namely, the actuator 702 rotates the wafer W heldon the holding table 701. The actuator 702 may include an encoder fordetecting a rotating position of the holding table 701. In this case,the exposure position of a peripheral portion Wd of the wafer W to beexposed by the exposure subunit 800 and the rotating position can berelated to each other.

The actuator 203 is, e.g., a linear actuator that moves the holdingtable 701 along the guide rail 704. Namely, the actuator 703 allows thewafer W held on the holding table 701 to be transferred between one endand the other end of the guide rail 704. Thus, the wafer W held on theholding table 701 can be moved between a first position near the inletand outlet port 601, and a second position near the exposure subunit800. The guide rail 704 extends linearly (e.g., like a straight line) inthe housing 600.

The exposure subunit 800 is located above the rotary holding subunit700. As shown in FIG. 18, the exposure subunit 800 includes a lightsource 801, an optical system 802, a mask 803 and an actuator 804. Thelight source 801 emits downward (toward the holding table 701) energybeam (e.g., ultraviolet ray) having a wavelength component capable ofexposing a resist film R. As the light source 801, an ultrahigh pressureUV lamp, a high pressure UV lamp, a low pressure UV lamp, an excimerlamp and so on may be used.

The optical system 802 is located below the light source 801. Theoptical system 802 is formed of at least one lens. The optical system802 converts the light from the light source 801 into a substantiallyparallel light, which light then reaches the mask 803. The mask 803 islocated below the optical system 802. The mask 803 has an opening 803 aby which an exposure area is adjusted. The parallel light from theoptical system 802 passes through the opening 803 a to reach aperipheral portion Wd of a front surface Wa of the wafer W held by theholding table 701.

The actuator 804 is connected to the light source 801. The actuator 804is, e.g., an elevation cylinder that moves the light source 801 upwardand downward. Namely, the light source 801 can be moved by the actuator804 between a first height position (lowered position) near the wafer Wheld by the holding table 701, and a second height position (elevatedposition) remote from the wafer W held by the holding table 701.

Structure of Controller

As shown in FIG. 19, the controller 10 includes, as functional modules,a reading unit M1, a storage unit M2, a processing unit M3 and aninstruction unit M4. These functional modules merely correspond to thefunctions of the controller 10 for the sake of conveniences, and do notnecessarily mean that a hardware constituting the controller 10 isdivided into these modules. The respective functional modules are notlimited to modules whose functions are realized by executing a program,but may be modules whose functions are realized by a dedicated electriccircuit (e.g., logic circuit) or an integrated circuit (ASIC:Application Specific Integrated Circuit).

The reading unit M1 reads out a program from a computer-readablerecording medium RM. The recording medium RM stores a program foroperating respective units of the substrate processing system 1. Therecording medium RM may be, for example, a semiconductor memory, anoptical memory disc, a magnetic memory disc, or a magneto optic memorydisc.

The storage unit M2 stores various data. The storage medium M2 storesvarious data when the process liquids L1, L2 are supplied to a wafer W(so-called process recipes), set data inputted by an operator through anexternal input apparatus (not shown) and so on, in addition to a programread out by the reading unit M1 from the recording medium RM,information on a wafer W read out from the storage medium 11 b and dataof images taken by the cameras 310, 410, 510.

The processing unit M3 processes various data. For example, theprocessing unit M3 generates, based on various data stored in thestorage unit M2, signals for operating the liquid processing unit U1(for example, rotary holding unit 20, liquid supplying units 30, 40),the thermal processing unit U2, the inspection unit U3 (for example, therotary holding subunit 200, cameras 310, 410, 510, illuminating modules320, 420, 520) and the periphery exposure unit U4 (for example, rotaryholding subunit 700, exposure subunit 800). In addition, the processingunit M3 generates information on a wafer W based on data of images takenby the cameras 310, 410, 510.

The instruction unit M4 transmits signals generated by the processingunit M3 to the respective apparatuses. The instruction unit M4 storesthe information on the wafer W generated in the processing unit M3 inthe storage medium 11 b. The instruction unit M4 transmits to thestorage medium 11 b an instruction signal for reading out theinformation on the wafer W stored in the storage medium 11 b.

A hardware of the controller 10 is formed of one or more controlcomputer(s), for example. The controller 10 has a circuit 10A as ahardware configuration, which is shown in FIG. 20, for example. Thecircuit 10A may be formed of an electric circuitry. Specifically, thecircuit 10A includes a processor 10B, a memory 10C (storage unit), astorage 10D (storage unit), a driver 10E and an input and output port10F. The processor 10B cooperates with at least one of the memory 10Cand the storage 10D to execute a program, so that a signal is inputtedand outputted through the input and output port 10F, whereby theaforementioned respective functional modules are realized. The memory10C and the storage 10D function as the storage unit M2. The driver 10Eis a circuit for driving the respective apparatuses of the substrateprocessing system 1. Signals are inputted and outputted through theinput and output port 10F, between the drive 10E and the variousapparatuses of the substrate processing system 1 (for example: storagemedium 11 b; rotating unit 21; holding unit 22, pumps 32, 42; valves 33,43; thermal processing unit U2; holding tables 201, 701; actuators 202,203, 702, 703, 804; cameras 310, 410, 510; light sources 322, 421, 522,801).

In this embodiment, although the substrate processing system 1 has onecontroller 10, the substrate processing system 1 may have a group ofcontrollers (control unit) formed of the plurality of controllers 10.When the substrate processing system 1 has a group of controllers, theabove-described functional modules may be respectively realized by theone controller 10, or may be realized by a combination of two or morecomputers 10. When the controller 10 is composed of a plurality ofcomputers (circuits 10A), the above-described functional modules may berealized by one computer (circuit 10A), or may be realized by acombination of two or more computers (circuits 10A). The controller 10may have the plurality of processors 10B. In this case, theabove-described functional modules may be respectively realized by oneprocessor 10B, or may be realized by a combination of two or moreprocessors 10B.

Method of Calculating Profile Line of Reference Wafer

Next, a method for calculating a profile line of a reference wafer bymeans of the inspection unit U3 is described with reference to FIG. 21.Herein, the reference wafer means a wafer whose warp amount (inparticular, peripheral warp amount) is known. The reference wafer may bea flat wafer. An evaluation index of a flatness of a wafer W may be, forexample, GBIR (Global Backside Ideal focal plane Range), SFQR (SiteFrontside least Squares focal plane Range), SBIR (Site Backside leastSquares focal plane Range), ROA (Roll OffAmount), ESFQR (Edge SiteFrontside least Squares focal plane Range), ZDD (Z-height DoubleDifferentiation), etc., which are defined by SEMI (Semiconductorequipment and materials international) standard. The reference wafer mayhave a flatness in which a maximum value of SFQR is about 100 nm, aflatness in which a maximum value of SFQR is about 42 nm, a flatness inwhich a maximum value of SFQR is about 32 nm, or a flatness in which amaximum value of SFQR is about 16 nm.

Because of the runout of the rotation shaft of the holding table 201,the assembling error (within the tolerance range) of the rotary holdingsubunit 200, and the manufacturing error (within the tolerance range) ofthe suction surface of the holding table 201 and so on, a wafer Wrotated by the holding table 201 may rotate eccentrically and theperiphery of the wafer W may oscillate vertically. The reference waferis used to obtain a reference value of the vertical oscillation of awafer W on the rotary holding subunit 200. Data on the reference valuemay be obtained by using the reference wafer before a wafer W isprocessed by the substrate processing system 1. Alternatively, data onthe reference value may be obtained by using the reference wafer aftermaintenance (adjustment, cleaning, etc.) of the substrate processingsystem 1. Alternatively, data on a reference value may be periodicallyobtained by using the reference wafer. A precise warp amount of theprocess wafer can be determined by comparing inspection data on aprocess wafer W (a wafer to be actually processed obtained) by using theinspection unit U3 with the reference value data.

Firstly, the controller 10 controls the respective units of thesubstrate processing system 1 such that the reference wafer istransported to the inspection unit U3 (step S11). Then, the controller10 controls the rotary holding subunit 200 such that the reference waferis held by the holding table 201. Then, the controller 10 controls therotary holding subunit 200 such that the holding table 201 is moved bythe actuator 203 from the first position to the second position alongthe guide rail 204. Thus, the peripheral portion of the reference waferis positioned between the illuminating module 420 and the mirror member430.

Then, the controller 10 controls the rotary holding subunit 200 torotate the holding table 201 by the actuator 202, whereby the referencewafer is rotated. Under this condition, the controller 10 controls theperiphery imaging subunit 400 such that the light source 421 is turnedon and that an image is taken by the camera 410 (step S12). In thismanner, the image of an end face of the reference wafer is taken overthe whole periphery of the reference wafer.

Then, based on the image of the end face of the reference wafer obtainedin the step S12, the profile line of the reference wafer is calculatedby the processing unit M3 (step S13). To be specific, the controller 10makes the processing unit M3 determine the upper edge and the lower edgeof the end face of the reference wafer from the image based on thecontrast difference, for example. Then, the controller 10 makes theprocessing unit U3 determine as the profile line a line passing throughthe median positions between the upper edge and the lower edge. Thus,the shape of the end face of the reference wafer is obtained. FIG. 25shows a profile line PO of the reference wafer by way of example.

Wafer Processing Method

Next, a method of processing a wafer W is described with reference toFIG. 22. Firstly, the controller 10 controls the respective units of thesubstrate processing system 1 such that a wafer W is transported fromthe carrier 11 to the inspection unit U3 where the wafer W is subjectedto an inspection process (step S21). In the inspection process of thewafer W, the warp amount of the wafer W is calculated, details of whichwill be described later. The calculated warp amount is related to thewafer W and stored in the storage unit M2.

Then, the controller 10 controls the respective units of the substrateprocessing system 1 such that the wafer W is transported to the liquidprocessing unit U1 where a resist film R is formed on a front surface Waof the wafer W (step S22). To be specific, the controller 10 controlsthe rotary holding unit 20 such that the wafer W is held by the holdingunit 22 and that the wafer W is rotated at a predetermined rotatingspeed. Under this condition, the controller 10 controls the pump 32, thevalve 33 and the nozzle 34 (more specifically, the drive unit thatdrives the nozzle 34) such that the process liquid L1 (resist liquid) isdischarged from the nozzle 34 onto the front surface Wa of the wafer Wwhereby an unsolidified coating film (unsolidified film) is formed allover the front surface Wa of the wafer W.

Then, the controller 10 controls the respective units of the substrateprocessing system 1 such that a part of the unsolidified film(peripheral portion of the unsolidified film) located at a peripheralportion Wd of the wafer W is removed (a so-called edge rinsing processis performed) (step S23). To be specific, the controller 10 controls therotary holding unit 20 such that the wafer W is held by the holding unit22, and that the wafer W is rotated at a predetermined rotating speed(e.g., about 1500 rpm). Under this condition, the controller 10 controlsthe pump 42, the valve 43 and the nozzle 44 (more specifically, thedrive unit that drives the nozzle 44) such that the process liquid L2(thinner which is an organic solvent) is discharged from the nozzle 44onto the peripheral portion Wd of the front surface Wa of the wafer Wwhereby the peripheral portion of the unsolidified film is dissolved.

Then, the controller 10 controls the respective units of the substrateprocessing system 1 such that the wafer W is transported from the liquidprocessing unit U1 to the thermal processing unit U2. Then, thecontroller 10 controls the thermal processing unit U2 such that theunsolidified film together with the wafer W is heated (so-called PAB)whereby the unsolidified film is solidified to be a solidified film(resist film R) (step S24).

If the periphery of the wafer W is warped, the height position of theperiphery of the wafer W may vary during the rotation of the wafer W. Anedge rinsing test was conducted to a wafer W having a warped periphery,without changing the height position of the nozzle 44. From this test,as shown in FIG. 24A, it was confirmed that there is a proportionalrelationship between the warp amount of the periphery of the wafer W andthe removal width RW (see FIG. 24B) of the peripheral portion of theresist film R. Thus, if such a wafer W is subjected to the edge rinsingprocess, the removal width RW may be non-uniform along the periphery ofthe wafer W. The removal width RW is a linear distance between theperiphery of the wafer W and the periphery of the resist film R measuredin the radial direction of the wafer W, when seen from the side of thefront surface Wa of the wafer W.

Thus, in the step S23, the controller 10 reads out the warp amount ofthe periphery of the wafer W, which was calculated in the step S21, fromthe storage unit M2, and determines, based on the warp amount, parametervalues such as the supply position from which the process liquid L2 isto be supplied by the nozzle 44 to the peripheral portion of the resistfilm R. Since the setting value of the removal width is set beforehandin the process recipe of the liquid processing unit U1 on the assumptionthat the wafer W is not warped, the controller 10 corrects the settingvalue based on the warp amount, such that the actual removal width ofthe peripheral portion of the unsolidified film corresponds to a desiredvalue. To be specific, the controller 10 controls the nozzle 44 suchthat the position of the discharge port of the nozzle 44 is adjusted, orcontrols the nozzle 44 such that the moving speed of the nozzle 44relative to the wafer W is adjusted, or controls the valve 43 such thatthe discharge flow rate of the process liquid L2 from the nozzle 44 isadjusted, in order that the removal width of the peripheral portion ofthe unsolidified film corresponds to the desired value.

In this manner, the process liquid L2 (organic solvent) is dischargedfrom the nozzle 44 onto the peripheral portion Wd of the front surfaceWa of each of the different wafers W, while changing the parametervalues such as the supply position from which the process liquid L2 isto be supplied by the nozzle 44. When one wafer W is subjected to theedge rinsing process, since the rotating speed of the wafer W in theedge rinsing process is relatively high (e.g., about 1500 rpm), thesupply position may be determined based on the average of warp amountsof the periphery of the wafer W. The removal width may be, e.g., about 1mm.

Then, the controller 10 controls the respective units of the substrateprocessing system 1 such that the wafer W is transported from the liquidprocessing unit U1 to the periphery exposure unit U4 where the wafer Wis subjected to a periphery exposure process (step S25). To be specific,the controller 10 controls the rotary holding subunit 700 such that thewafer W is held by the holding table 701 and that the wafer W is rotatedat a predetermined rotating speed (e.g., about 30 rpm). Under thiscondition, the controller 10 controls the exposure subunit 800 such thatthe light source 801 emits predetermined energy beam (ultraviolet ray)to the resist film R located at the peripheral portion Wd of the frontsurface Wa of the wafer W. If the center axis of the holding table 701and the center axis of the wafer W do not coincide with each other, thewafer W is eccentrically rotated on the holding table 701. In this case,the controller 10 may control the actuator 703 such that the holdingtable 701 moves along the guide rail 704 depending on the eccentricamount of the wafer W.

When the periphery of the wafer W is warped, the height position of theperiphery of the wafer W may vary during the rotation of the wafer W. Inthis case, when the peripheral portion Wd of the front surface Wa of thewafer W is irradiated with energy beam, the peripheral portion Wd mayhave areas on which the energy beam converges and areas on which theenergy beam does not converge. Thus, the exposure amount of theperipheral portion Wd may be insufficient.

Thus, in the step S25, the controller 10 reads out the warp amount ofthe periphery of the wafer W, which is calculated in the step S21, anddetermines, based on the warp amount, the position of the exposuresubunit 800 relative to the peripheral portion Wd. Since the settingvalue of the exposure width is set beforehand in the process recipe ofthe periphery exposure unit U4 on the assumption that the wafer W is notwarped, the controller 10 corrects the setting value based on the warpamount, such that the actual exposure width of the peripheral portion ofthe resist film R corresponds to a desired value. To be specific, thecontroller 10 controls the actuator 703 such that the horizontalposition of the wafer W relative to the exposure subunit 800 isadjusted, or controls actuator 804 to adjust the gap (optical pathlength) between the wafer W and the exposure subunit 800, in order thatthe exposure width of the peripheral portion of the resist film Rcorresponds to the desired value. For example, if the periphery of thewafer W is warped to approach the exposure subunit 800 (warped upward),the horizontal position of the wafer W relative to the exposure subunit800 is adjusted such that the exposure subunit 800 approaches center ofthe wafer W, or the exposure subunit 800 is moved upward. On the otherhand, if the periphery of the wafer W is warped to be removed from theexposure subunit 800 (warped downward), the horizontal position of thewafer W relative to the exposure subunit 800 is adjusted such that theexposure subunit 800 approaches the periphery of the wafer W, or theexposure subunit 800 is moved downward. For example, when the peripheryof the wafer W is warped at about 200 μm, the horizontal position of thewafer W relative to the exposure subunit 800 is adjusted at about 0.1mm, for example, or the height position of the exposure subunit 800 withrespect to the wafer W is adjusted at about 0.2 mm, for example.

In this manner, the peripheral portion Wd of the front surface Wa ofeach of the wafers W is irradiated with the energy beam, while changingthe position of the exposure subunit 800 relative to the wafer W. Whenone wafer W is subjected to the periphery exposure process, since therotating speed of the wafer W is relatively low (e.g., about 30 rpm),the position of the exposure subunit 800 relative to the wafer W may bedetermined based on the warp amount relative to coordinates of theperiphery of the wafer W. The exposure width is larger than the removalwidth in the edge rinsing process, and may be, e.g., about 1.5 mm.

Then, the controller 10 controls the respective units of the substrateprocessing system 1 such that the wafer W is transported from theperiphery exposure unit U4 to the inspection unit U3 where the wafer Wis subjected to an inspection process (step S26). The inspection processof the wafer W in this step is the same as that of the step S21, anddetails thereof will be described later.

Then, the controller 10 controls the respective units of the substrateprocessing system 1 such that the wafer W is transported from theinspection unit U3 to the exposure apparatus 3 where the wafer W issubjected to an exposure process (step S27). To be specific, in theexposure apparatus 3, the resist film R formed on the front surface Waof the wafer W is irradiated with predetermined energy beam in apredetermined pattern. Thereafter, a resist pattern is formed on thefront surface Wa of the wafer W through a developing process in the unitprocessing block 17.

Wafer Inspection Method

A method of inspecting a wafer W (process substrate) is described indetail with reference to FIG. 23. Firstly, the controller 10 controlsthe respective units of the substrate processing system 1 such that thewafer W is transported to the inspection unit U3 (step S31). Then, thecontroller 10 controls the rotary holding subunit 200 such that thewafer W is held by the holding table 201. Then, the controller 10controls the rotary holding subunit 200 such that the holding table 201is moved by the actuator 203 from the first position to the secondposition along the guide rail 204. At this time, the controller 10controls the front surface imaging subunit 300 such that the lightsource 322 is turned on and that an image is taken by the camera 310(step S32; an imaging step of the front surface Wa of the wafer W).Thus, the whole front surface Wa of the wafer W is imaged. When thewafer W reaches the second position and the imaging by the camera 310 iscompleted, data of the image taken by the camera 310 are transmitted tothe storage unit M2. Upon completion of the imaging by the camera 310,the peripheral portion of the wafer W is positioned between theilluminating module 420 and the mirror member 430.

Then, the controller 10 controls the rotary holding subunit 200 suchthat the holding table 201 is rotated by the actuator 202. Thus, thewafer W is rotated. Under this condition, the controller 10 controls theperiphery imaging subunit 400 such that the light source 421 is turnedon and that an image is taken by the camera 410 (step S32; an imagingstep of the end face Wc of the wafer W and an imaging step of theperipheral portion Wd of the front surface Wa of the wafer W). Thus, theend face Wc of the wafer W and the peripheral portion Wd of the frontsurface Wa of the wafer W are imaged over the whole periphery of thewafer W. At the same time, the controller 10 controls the rear surfaceimaging subunit 500 such that the light source 522 is turned on and thatan image is taken by the camera 510 (step S32; an imaging step of therear surface Wb of the wafer W). After the wafer W has been rotated forone rotation so that the imaging by the cameras 410, 510 is completed,data of the images taken by the cameras 410, 510 are transmitted to thestorage unit M2.

Then, the controller 10 makes the processing unit M3 process the data ofthe images, which are taken in the step S32, so as to detect defects ofthe wafer W (step S33). The defect detection by the image processing canbe performed in various ways, and defects may be detected based on thecontrast difference, for example. The controller 10 makes the processingunit M3 judge the type of the defect (for example, flaw, crack, scratch,insufficient formation of the coating film, etc.) based on the size, theshape, the location, etc., of the defect.

Then, the controller 10 makes the processing unit M3 judge whether thedefect detected in the step S33 is allowable or not. If it is judgedthat the wafer W has an unallowable defect (NO in step S34), the wafer Wis not subjected to a succeeding process, and the controller 10 controlsthe respective units of the substrate processing system 1 such that thewafer W is returned to the carrier 11 (step S35). Thus, the wafer W isnot subjected to the exposure process in the step S26 (see mark “A” inFIGS. 22 and 23).

On the other hand, if it is judged that the wafer W has no defect or thewafer W has an allowable defect (YES in step S34), the controller 10makes the processing unit M3 calculate a profile line of the wafer Wbased on the image of the end face Wc of the wafer W obtained in thestep S32 (step S36). To be specific, the controller 10 recognizes theupper edge and the lower edge of the end face Wc of the wafer W from theimage based on the contrast difference, for example. Then, thecontroller 10 makes the processing unit U3 determine, as a profile line,a line passing through the median positions between the upper edge andthe lower edge. Thus, the shape of the end face Wc of the wafer W isobtained.

By way of example, FIG. 25 shows three types of profile lines P1 to P3of the wafer W. The profile line P1 is like a sine curve that intersectsthe profile line P0 of the reference wafer. The profile line P2 extendsalong and below the profile line P0 of the reference wafer. The profileP3 extends along and above the profile line P0.

Then, the controller 10 makes the processing unit M3 calculate the warpamount of the wafer W by correcting the profile line P1 to P3 obtainedin the step S36 using the profile line P0 that is obtained in the stepS13 (step S37). To be specific, the controller 10 makes the processingunit M3 calculate the difference of the profile line of the wafer W fromthe profile line of the reference wafer (i.e., subtracting the profileline of the reference wafer from the profile line of the wafer W) so asto calculate the warp amount of the wafer W at each coordinate value(i.e., each angular position).

FIG. 26 shows a warp amount Q1 which is obtained by subtracting theprofile line P0 of the reference wafer from the profile line P1 of thewafer W, a warp amount Q2 which is obtained by subtracting the profileline P0 of the reference wafer from the profile line P2 of the wafer W,and a warp amount Q3 which is obtained by subtracting the profile lineP0 of the reference wafer from the profile line P3 of the wafer W. Fromthe warp amount Q1, it can be understood that the periphery of the waferW undulates up and down. Thus, it can be judged that the wafer W has ahyperbolic paraboloid shape as shown in FIG. 27A. From the warp amountQ2, it can be understood that the periphery of the wafer W is lowered.Thus, it can be judged that the wafer W has an upwardly convexparaboloid of revolution shape as shown in FIG. 27B. From the warpamount Q3, it can be understood that the periphery of the wafer W israised. Thus, it can be judged that the wafer W has a downwardly convexparaboloid of revolution shape as shown in FIG. 27C.

Then, the controller 10 makes the processing unit M3 judge whether thewarp amount obtained in the step S37 is within an allowable range ornot. An allowable range of the warp amount may be set by a numericalvalue in an overlay (OL) control of the exposure apparatus 3. If it isjudged that the warp amount is too large to allow (NO in step S38), thecontroller 10 makes the storage unit M2 store information that the waferW is not subjected to the exposure process, in relation to the wafer W(step S39). Thus, the wafer W is not subjected to the exposure processin the step S26 (see mark “A” in FIGS. 22 and 23).

On the other hand, if it is judged that the warp amount is small andallowable (YES in step S38), the controller 10 completes the inspectionprocess. At this time, the controller 10 controls the respective unitsof the substrate processing system 1 such that the wafer W istransported from the inspection unit U3 to the exposure apparatus 3.

Operation

In this embodiment, the step S37 calculates the warp amount of the waferW, and the step S23 determines, based on the warp amount, the supplyposition from which the process liquid L2 is to be supplied by thenozzle 44 to the peripheral portion of the resist film R, and dissolvesthe peripheral portion by the process liquid L2 supplied from the supplyposition so as to remove the same from the wafer W. Thus, since thesupply position of the process liquid L2 to the peripheral portion ofthe resist film R suitable for the warp amount of the periphery of thewafer W can be properly set, the removal width RW of the peripheralportion can be made more uniform. As a result, even if the wafer W iswarped, the periphery of the wafer W can be properly processed. Inaddition, since circuits can be formed on the front surface Wa of thewafer W in areas close to the periphery, higher integration of circuitson the wafer W is promoted whereby the wafer W can be more efficientlyutilized.

Similarly, in this embodiment, the step S37 calculates the warp amountof the wafer W, and the step S25 determines the exposure width based onthe warp amount. Thus, since the exposure width suitable for the warpamount of the periphery of the wafer W can be properly determined, theexposure width of the peripheral portion can be made more uniform. Thus,the removal width of the peripheral portion of the resist film R can bemade more uniform. As a result, even if the wafer W is warped, theperiphery of the wafer W can be properly processed. In addition, sincecircuits can be formed on the front surface Wa of the wafer W in areasclose to the periphery, higher integration of circuits on the wafer W ispromoted whereby the wafer W can be more efficiently utilized.

In this embodiment, the step S37 calculates the warp amount of the waferW by correcting the profile line P1 to P3 of the wafer W by using theprofile line P0 of the reference wafer. Thus, by subtracting the profileline P0 of the reference wafer from the profile line P1 to P3 of thewafer W, the warp amount of the wafer W can be easily calculated fromthe profile line P0 and the profile line P1 to P3.

In this embodiment, whether the warp amount obtained in the step 37 iswithin an allowable range or not is judged. If the warp amount is toolarge to allow (NO in step S38), the wafer W is not subjected to theexposure process. Namely, a wafer W that is difficult to be exposed bythe exposure apparatus 3 can be discriminated beforehand and the wafer Wcan be excluded from the exposure process. Thus, the process efficiencyof wafer W can be improved.

In this embodiment, whether the defect detected in the step S33 iswithin an allowable range or not is judged. If the wafer W has anunallowable defect (NO in step S34), the wafer W is not subjected to asucceeding process. Namely, the defect (for example, flaw, crack,scratch, etc.) on the front surface Wa of the wafer W or in the vicinityof the periphery of the wafer W can be detected, and the wafer W can beexcluded from various processes. Thus, the process efficiency of wafer Wcan be improved.

In this embodiment, the size of the holding unit 22, the size of theholding table 201 and the size of the holding table 701 aresubstantially the same. Thus, stresses induced in parts between each ofthe holding unit 22, the holding table 201 and the wafer W aresubstantially the same. Thus, when the warp amount of the wafer W iscalculated in the step S37, when the edge rinsing process is performedin the step S23, and when the periphery exposure process is performed inthe step S25, variation of the warp amount is about the same. As aresult, it is easy to correct the setting value of the removal width inthe step S23, and to correct the setting value of the exposure width inthe step S25, based on the warp amount calculated in the step S37.

In this embodiment, the mirror member 43 has the reflecting surface 432that is inclined with respect to the rotation axis of the holding table201, and that opposes the end face Wc and the peripheral portion Wd ofthe back surface Wb of the wafer W held by the holding table 201. Inaddition, in this embodiment, the imaging device 412 of the camera 410receives two light beams through the lens 411, one coming from theperipheral portion Wd of the front surface Wa of the wafer W held by theholding table 201, and the other coming from the end face of the wafer Wheld by the holding table 201 to fall on the reflecting surface 432 ofthe mirror member 430 and then being reflected by the reflecting surface432 of the mirror member 430. Thus, both the peripheral portion Wd ofthe front surface Wa of the wafer W and the end face Wc of the wafer Ware simultaneously imaged by the one camera 410. Thus, since a pluralityof cameras are no longer necessary, a space for installation of thesecameras is unneeded. In addition, since a mechanism for moving thecamera 410 is unnecessary, a space for installation of the mechanism isunneeded. Thus, in this embodiment, the inspection unit U3 can have asignificantly simplified structure. As a result, the inspection unit U3can achieve reduction in size and decrease in cost, while avoidingequipment failure.

In this embodiment, the reflecting surface 432 is a curved surface thatis recessed away from the end face Wc of the wafer W held by the holdingtable 201. Thus, the mirror image of the end face Wc of the wafer Wreflected on the reflecting surface 432 is enlarged. For example, if thereflecting surface 432 is not a curved surface, the end face Wc of thewafer W in the image on the imaging device has a width corresponding toabout 20 pixels. On the other hand, if the reflecting surface 432 is acurved surface as described above, the width of the end face Wc of thewafer W in the image on the imaging device is enlarged about 1.5 timesin the thickness direction. Thus, a more detailed image of the end faceWc of the wafer W can be obtained. As a result, by processing thedetailed image, the end face Wc of the wafer W can be more preciselyinspected.

The optical path length of the light, which comes from the end face Wcof the wafer W and is reflected by the reflecting surface 432 of themirror member 430 to reach the lens 411, is longer than the optical pathlength of the light, which comes from the peripheral portion Wd of thefront surface Wa of the wafer W to reach the lens 411, because of thereflection by the mirror member 430. However, in this embodiment, thefocus adjusting lens 427 is disposed in the light path extending fromthe reflecting surface 432 of the mirror member 430 to the lens 411. Thefocus adjusting lens 427 is configured to adjust an image formingposition, at which the image of the end face Wc of the wafer W isformed, onto the imaging device 412. Thus, owing to the focus adjustinglens 427, the image forming position of the end face Wc of the wafer Wcan be adjusted onto the imaging device 412, whereby both the images ofthe peripheral portion Wd of the front surface Wa of the wafer W and theend face Wc of the wafer W are clear. As a result, by processing theclear image, the end face Wc of the wafer W can be more preciselyinspected.

In this embodiment, the illuminating module 420 irradiates thereflecting surface 432 of the mirror member 430 with diffused light inorder to allow the diffused light, which comes from the illuminatingmodule 420 and then is reflected by the reflecting surface 432 of themirror member 430, to fall on the end face Wc of the wafer W held by theholding table 201. Thus, the diffused light enters the end face Wc ofthe wafer W from various directions. Thus, the entire end face Wc of thewafer W can be uniformly illuminated. As a result, the end face Wc ofthe wafer W can be imaged more clearly.

In this embodiment, the light emitted from the light source 421 isscattered by the light scattering member 422, enlarged by thecylindrical lens 425 and further diffused by the light diffusing member426. Thus, the diffused light enters the end face Wc of the wafer W fromvarious directions. Thus, the entire end face Wc of the wafer W can beuniformly illuminated. As a result, the end face Wc of the wafer W canbe imaged more clearly.

Other Embodiments

The embodiment according to the disclosure has been described in detail,but the above embodiment can be variously modified within the scope ofthe present invention. For example, the reflecting surface 432 hasanother shape (e.g., flat surface) other than a curved face, as long asthe reflecting surface 432 is inclined with respect to the rotation axisof the holding table 201 and opposes the end surface Wc and the backsurface Wb of the wafer W held by the holding table 201.

The focus adjusting lens 427 may be omitted from the periphery imagingsubunit 400.

Any of the light scattering member 422, the cylindrical lens 425 and thelight diffusing member 426 may be omitted from the periphery imagingsubunit 400.

The inspection unit U3 may be disposed in the shelf units U10, U11. Forexample, the inspection unit U3 may be provided in the cells of theshelf units U10, U11, which are located correspondingly to the unitprocessing units 14 to 17. In this case, a wafer W is directly deliveredto the inspection unit U3 by the arms A1 to A8 that transport the waferW.

For the purposed of calculating the warp amount of the wafer W, animaging module capable of imaging only the end face Wc of the wafer Wmay be used, without using the periphery imaging subunit 400 capable ofimaging both the end face Wc of the wafer W and the peripheral portionWd of the front surface Wa thereof. The front surface Wa of the wafer W,the rear surface Wb thereof, the end face Wc thereof and the peripheralportion Wd of the front surface Wa thereof may be imaged by differentcameras. At least images of two of the front surface Wa of the wafer W,the rear surface Wb thereof, the end face Wc thereof and the peripheralportion Wd of the front surface Wa thereof may be simultaneously takenby one camera.

Before and after the heating process of the step S24, the waferinspection process may be performed in the same inspection unit U3, orthe wafer inspection process may be performed in the differentinspection units U3.

The inspection process of the wafer W in the step S25 may be performed,not after the periphery exposure process in the step S24, but after theheating process in the thermal heating unit U2 in the step S22(so-called PAB) and after the exposure process in the step S26.

As shown in FIG. 28, the wafer inspection process (re-inspectionprocess) (step S28) may be performed by the inspection unit U3 betweenthe heating process in the step S24 and the periphery exposure processin the step S25. At this time, the periphery exposure process in thestep S25 may determine the exposure width based on the warp amountcalculated by the wafer inspection process in the step S28. In thiscase, since the exposure width can be more properly determined dependingon the warp of the wafer W having been subjected to the heating processin the step S24, the exposure width of the peripheral portion of theresist film R can be made more uniform. Thus, by developing the wafer Wafter the periphery exposure process, the removal width of theperipheral portion can be made more uniform. In addition, at this time,whether the warp amount calculated by the wafer inspection process inthe step S28 is within an allowable range or not may be judged. If thewarp amount is too large to allow, the wafer W is not subjected to theexposure process. Namely, a wafer W that is difficult to be exposed bythe periphery exposure unit U4 can be discriminated beforehand and thewafer W can be excluded from the periphery exposure process. Thus, theprocess efficiency of wafer W can be improved.

As shown in FIG. 29, the steps S24 to S27 may be performed withoutperforming the edge rinsing process of the step S23. Although not shown,after performing the heating process of the step S24, the succeedingsteps of S26 and S27 may be performed without performing the peripheryexposure process of the step S25.

The warp amount calculated by the wafer inspection process (S21) in theinspection unit U2 may be utilized in the succeeding heating process(step S24) in the thermal processing unit U2. For example, judgment onwhether the wafer W is to be sucked to the heating plate of the thermalprocessing unit U2, and controlling of the suction amount, the suctionposition, the suction pressure, the suction timing and so on may beperformed based on the warp amount.

1. A substrate processing apparatus comprising: a coating liquidsupplying unit configured to supply a coating liquid onto a surface of aprocess substrate; a solvent supplying unit configured to supply a firstorganic solvent and a second organic solvent onto a surface of a processsubstrate; a first rotary holding unit configured to hold and rotate theprocess substrate; at least one camera; and a control unit, wherein thecontrol unit is configured to control the substrate processing apparatusto perform a procedure including: a first step that takes an image of anend face of a reference substrate, whose warp amount is known, over awhole periphery of the reference substrate by means of said at least onecamera; a second step that performs image processing of the image takenin the first step, thereby to obtain shape data of the end face of thereference substrate over a whole periphery of the reference substrate; athird step that takes an image of an end face of a process substrateover a whole periphery of the process substrate by means of said atleast one camera; a fourth step that performs image processing of theimage taken in the third step, thereby to obtain shape data of the endface of the process substrate over a whole periphery of the processsubstrate; a fifth step that calculates a warp amount of the processsubstrate based on the shape data obtained in the second step and theshape data obtained in the fourth step; a sixth step that controls thecoating liquid supplying unit and the first rotary holding unit andsupplies a coating liquid to a surface of the rotating process substratethereby to form a coating film on the surface of the process substrate;a seventh step that controls the solvent supplying unit and the firstrotary holding unit, determines a supply position from which an organicsolvent is to be supplied to a peripheral portion of the coating film,based on the warp amount calculated in the fifth step, and supplies theorganic solvent from the supply position to dissolve the peripheralportion of the coating film and remove the same from the rotatingprocess substrate.
 2. The substrate processing apparatus according toclaim 1, further comprising an irradiating unit configured to irradiatea peripheral portion of the surface of the process substrate with energybeam, wherein the control unit is configured to control the irradiatingunit to perform a periphery exposure step that exposes, after theseventh step, the coating film in the peripheral portion of the surfaceof the process substrate at a predetermined exposure width over thewhole periphery of the process substrate, and wherein in the peripheryexposure step the exposure width is determined based on the warp amountcalculated in the fifth step.
 3. The substrate processing apparatusaccording to claim 1, further comprising a memory unit that storesinformation on the process substrate, wherein the control unit isconfigured to control the substrate processing apparatus to perform theprocedure further including: an eighth step that heats the coating filmafter the seventh step; a ninth step that takes, after the eighth step,an image of the end face of the process substrate over the wholeperiphery of the process substrate by means of said at least one camera;a tenth step that performs image processing of the image taken in theninth step, thereby to obtain shape data of the end face of the processsubstrate over the whole periphery of the process substrate; an eleventhstep that calculates a warp amount of the process substrate based on theshape data obtained in the second step and the shape data obtained inthe tenth step; and a storing step that stores in the memory unitinformation that the process substrate should not be subjected to anexposure process, if the warp amount calculated in the eleventh step isgreater than a threshold value.
 4. The substrate processing apparatusaccording to claim 3, further comprising a first processing chamber inwhich the third step that takes the image of the process substrate isperformed, and a second processing chamber in which the tenth step thattakes the image of the process substrate is performed, the firstprocessing chamber being different from the second processing chamber.5. The substrate processing apparatus according to claim 1, furthercomprising an irradiating unit configured to irradiate a peripheralportion of the surface of the process substrate with energy beam,wherein the control unit is configured to control the substrateprocessing apparatus to perform the procedure further including: aneighth step that heats the coating film after the seventh step; a ninthstep that takes, after the eighth step, an image of the end face of theprocess substrate over the whole periphery of the process substrate bymeans of said at least one camera; a tenth step that performs imageprocessing of the image taken in the ninth step, thereby to obtain shapedata of the end face of the process substrate over the whole peripheryof the process substrate; an eleventh step that calculates a warp amountof the process substrate based on the shape data obtained in the secondstep and the shape data obtained in the tenth step; and a peripheryexposure step that controls, after the ninth step, the irradiating unitand exposes the coating film in the peripheral portion of the surface ofthe process substrate at a predetermined exposure width over the wholeperiphery of the process substrate, and wherein in the peripheryexposure step the exposure width is determined based on the warp amountcalculated in the fifth step.
 6. The substrate processing apparatusaccording to claim 5, further comprising a memory unit that storesinformation on the process substrate, wherein the control unit isconfigured to control the substrate processing apparatus to perform theprocedure further including: a storing step that stores in the memoryunit information that the process substrate should not be subjected toan exposure process, if the warp amount calculated in the eleventh stepis greater than a threshold value.
 7. The substrate processing apparatusaccording to claim 1, further comprising a second rotary holding unitconfigured to hold and rotate the process substrate, wherein the controlunit is configured to control the second rotary holding unit to rotatethe process substrate in the third step, and wherein during rotation ofthe process substrate the image of the end face of the process substrateover the whole periphery of the process substrate is taken by means ofsaid at least one camera in the third step, and wherein parts of thefirst rotary holding unit for holding the process substrate havesubstantially the same size as parts of the second rotary holding unitfor holding the process substrate.
 8. The substrate processing apparatusaccording to claim 1, further comprising: a second rotary holding unitconfigured to hold and rotate the process substrate; and a mirror memberhaving a reflecting surface that opposes an end face of the substrateand a peripheral portion of a back surface of the substrate held by thesecond rotary holding unit, the reflecting surface being inclined withrespect to a rotation axis of the rotary holding unit; wherein one ofsaid at least one camera has an imaging device that receives both firstlight and second light through a lens, the first light coming from aperipheral portion of a front surface of the substrate held by thesecond rotary holding unit, and the second light being a reflected lightof second light which comes from the end face of the substrate held bythe second rotary holding unit and is reflected by the reflectingsurface.
 9. The substrate processing apparatus according to claim 1,wherein: the reference substrate is flat; wherein the control unit isconfigured to control the substrate processing apparatus such that: thesecond step obtains, as the shape data of the end face of the referencesubstrate, data on a first profile line passing through a center of theend face of the reference substrate; the fourth step obtains, as theshape data of the end face of the process substrate, data on a secondprofile line passing through a center of the end face of the processsubstrate; and the fifth step calculates the warp amount of the processsubstrate based on the data on the first profile line and the data onthe second profile line.
 10. The substrate processing apparatusaccording to claim 1, wherein the control unit is configured to controlthe substrate processing apparatus to perform the procedure furtherincluding: a peripheral portion imaging step that takes an image of aperipheral portion of a surface of the process substrate by means ofsaid at least one camera; and an inspecting step that inspects conditionof the end face of the process substrate through image processing of theimage taken in the fourth step, and inspects condition of the peripheralportion of the process substrate through image processing of the imagetaken in the peripheral portion imaging step.
 11. A substrate processingapparatus comprising: a coating liquid supplying unit configured tosupply a coating liquid onto a surface of a process substrate; anirradiating unit configured to irradiate a peripheral portion of thesurface of the process substrate with energy beam; at least one camera;and a control unit, wherein the control unit is configured to controlthe substrate processing apparatus to perform a procedure including: afirst step that takes an image of an end face of a reference substrate,whose warp amount is known, over a whole periphery of the referencesubstrate by means of said at least one camera; a second step thatperforms image processing of the image taken in the first step, therebyto obtain shape data of the end face of the reference substrate over awhole periphery of the reference substrate; a third step that takes animage of an end face of a process substrate over a whole periphery ofthe process substrate by means of said at least one camera; a fourthstep that performs image processing of the image taken in the thirdstep, thereby to obtain shape data of the end face of the processsubstrate over a whole periphery of the process substrate; a fifth stepthat calculates a warp amount of the process substrate based on theshape data obtained in the second step and the shape data obtained inthe fourth step; a sixth step that controls the coating liquid supplyingunit and supplies a coating liquid to a surface of the process substratethereby to form a coating film on the surface of the process substrate;a periphery exposure step that controls, after the sixth step, theirradiating unit and exposes the coating film in the peripheral portionof the surface of the process substrate at a predetermined exposurewidth over the whole periphery of the process substrate, and wherein inthe periphery exposure step the exposure width is determined based onthe warp amount calculated in the fifth step.
 12. The substrateprocessing apparatus according to claim 11, further comprising a heatingunit configured to heat the process substrate, wherein the control unitis configured to control the substrate processing apparatus to performthe procedure further including: a seventh step that heats, after thesixth step, the coating unit by means of the heating unit, wherein thethird, fourth and fifth steps are performed after the seventh step. 13.The substrate processing apparatus according to claim 12, furthercomprising a memory unit that stores information on the processsubstrate, wherein the control unit is configured to control thesubstrate processing apparatus to perform the procedure furtherincluding: a storing step that stores in the memory unit informationthat the process substrate should not be subjected to an exposureprocess, if the warp amount calculated in the fifth step is greater thana threshold value.
 14. The substrate processing apparatus according toclaim 11, further comprising first and second rotary holding unit eachconfigured to hold and rotate the process substrate, wherein the controlunit is configured to control the first rotary holding unit to rotatethe process substrate in the third step, and wherein during rotation ofthe process substrate the image of the end face of the process substrateover the whole periphery of the process substrate is taken by means ofsaid at least one camera in the third step, wherein the control unit isconfigured to control the second rotary holding unit to rotate theprocess substrate in the periphery exposure step, and wherein duringrotation of the process substrate the coating film in the peripheralportion of the surface of the process substrate is exposed at apredetermined exposure width over the whole periphery of the processsubstrate, and wherein parts of the first rotary holding unit forholding the process substrate have the same size as parts of the secondrotary holding unit for holding the process substrate.
 15. The substrateprocessing apparatus according to claim 11, further comprising: a secondrotary holding unit configured to hold and rotate the process substrate;and a mirror member having a reflecting surface that opposes an end faceof the substrate and a peripheral portion of a back surface of thesubstrate held by the second rotary holding unit, the reflecting surfacebeing inclined with respect to a rotation axis of the rotary holdingunit; wherein one of said at least one camera has an imaging device thatreceives both first light and second light through a lens, the firstlight coming from a peripheral portion of a front surface of thesubstrate held by the second rotary holding unit, and the second lightbeing a reflected light of second light which comes from the end face ofthe substrate held by the second rotary holding unit and is reflected bythe reflecting surface.
 16. The substrate processing apparatus accordingto claim 11, wherein: the reference substrate is flat; wherein thecontrol unit is configured to control the substrate processing apparatussuch that: the second step obtains, as the shape data of the end face ofthe reference substrate, data on a first profile line passing through acenter of the end face of the reference substrate; the fourth stepobtains, as the shape data of the end face of the process substrate,data on a second profile line passing through a center of the end faceof the process substrate; and the fifth step calculates the warp amountof the process substrate based on the data on the first profile line andthe data on the second profile line.
 17. The substrate processingapparatus according to claim 11, wherein the control unit is configuredto control the substrate processing apparatus to perform the procedurefurther including: a peripheral portion imaging step that takes an imageof a peripheral portion of a surface of the process substrate by meansof said at least one camera; and an inspecting step that inspectscondition of the end face of the process substrate through imageprocessing of the image taken in the fourth step, and inspects conditionof the peripheral portion of the process substrate through imageprocessing of the image taken in the peripheral portion imaging step.